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(1 國網(wǎng)河北省電力有限公司經(jīng)濟技術研究院, 石家莊 050000; 2 河北大學建筑工程學院, 保定 071002)
摘要: 為了研究非均勻地基不同區(qū)域樁長變化對樁筏基礎沉降特性的影響,以某變電站樁筏基礎工程為背景,采用 PLAXIS 3D 軟件建立上部荷載?樁筏基礎?非均勻地基三維有限元模型,分析了 4 種非等樁長設計方案下的筏板與地基沉降變形特性. 結(jié)果表明:筏板沉降分布形態(tài)、最大沉降量及其出現(xiàn)的位置均隨筏板下不同區(qū)域樁長的變化而變化. 方案 1 和方案 2 的樁長隨持力層頂面埋深變化而變化,樁端進入較硬的持力層,但筏板下不同區(qū)域的樁長差異較大,筏板沉降非對稱分布,最大差異沉降 13. 70~ 15. 13mm;方案 4 為等樁長,但由于土層分布不均勻,不同區(qū)域的樁側(cè)阻力和樁端阻力發(fā)揮各異,筏板沉降亦為非對稱分布,最大差異沉降仍達 12. 57mm;方案 3 各區(qū)樁長變化較小,筏板沉降分布相對較為均勻,其最大沉降量和差異沉降相比方案 1 分別降低 22. 8%和 37. 5%,說明此時樁長與土層分布相協(xié)調(diào),沉降控制效果較好.
關鍵詞: 樁筏基礎; 非均勻地基; 變樁長; 沉降; 協(xié)同分析
中圖分類號:TU473. 1 文獻標志碼:A 文章編號:1002?848X(2022)08?0124?07
DOI:10. 19701 / j.jzjg.20210625
Three dimensional finite element cooperative analysis of settlement control of variable pile lengthin non?uniform foundation
WU Hailiang1, XING Lin1, ZHANG Wuchen1, ZHANG Haiqing2
(1 Economic and Technological Research Institute, State Grid Hebei Electric Power Co., Ltd., Shijiazhuang 050000,China; 2 College of Civil Engineering and Architecture, Hebei University, Baoding 071002, China)
Abstract: In order to study the influence of pile length changes in different areas of non?uniform foundation on thesettlement characteristics of pile?raft foundation, taking the pile?raft foundation project of a substation as the background,the PLAXIS 3D software was used to establish a three?dimensional finite element model of upper load?pile?raft foundation?non?uniform foundation, and the settlement and deformation characteristics of the raft and foundation under four unequalpile length design schemes were analyzed. The results show that the distribution form of the raft settlement, the maximumsettlement value and its occurrence position all change with the change of the pile length in different areas under the raft.The pile lengths of scheme 1 and scheme 2 change with the buried depth of the top surface of the bearing layer, and the pileends enter the harder bearing layer. But the pile lengths in different areas under the raft are quite different, and the raftsettlement is distributed asymmetrically. The maximum differential settlement is 13. 70~ 15. 13mm. Scheme 4 is equal to thelength of the pile, but due to the uneven distribution of soil layers, and the pile side resistance and pile end resistance indifferent areas play different roles, and the raft settlement is also asymmetrically distributed, and the maximum differentialsettlement is still up to 12. 57mm. The change of pile length in each area of scheme 3 is small, and the distribution of raftsettlement is relatively uniform. Compared with scheme 1, the maximum settlement and differential settlement of scheme 3are reduced by 22. 8% and 37. 5% respectively, which shows that the pile length is suitable for the distribution of soillayer, and the settlement control effect is fairly good.
Keywords:pile?raft foundation; non?uniform foundation; variable pile length; settlement; collaborative analysis
∗國網(wǎng)河北省電力有限公司科技項目資助“基于數(shù)值模擬的變電站軟弱地基分析技術研究”(B704JY200081).
第一作者:吳海亮,碩士,工程師,主要從事變電站結(jié)構設計工作,Email:463289609@ qq.com.
[引用本文] 吳海亮,邢琳,張戊晨,等. 非均勻地基變樁長沉降控制三維有限元協(xié)同分析[ J]. 建筑結(jié)構,2022,52(8):124?130,65. WU Hailiang, XING Lin, ZHANG Wuchen, et al. Three dimensional finite element cooperative analysisof settlement control of variable pile length in non?uniform foundation[J]. Building Structure,2022,52(8):124?130,65.
